JPH10275283A - Fire alarm - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and speedily grasp the number of responding sensors on a reception part side. SOLUTION: The respective fire sensors 4 have constant current control means making prescribed constant current flow between a common line 2 and a line 3 based on a signal from a reception part and the reception part has a counting means discriminating the number (n) of the responding fire sensors from discharge time when discharging is executed from a capacitor to the common line 2 and the line 3. Thus, the reception part can discriminate the number (n) based on discharge time from the capacitor based on a current value between the common line 2 and the line 3, which is obtained by adding constant current passing through the responding fire sensors. In such a case, the sensors which do not respond cannot be specified but the presence or absence of abnormality can easily and speedily be grasped from the number of the responding sensors.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fire alarm for checking fire detectors scattered in a dwelling unit from outside the dwelling unit.

[0002]

2. Description of the Related Art Conventionally, an operation test of a fire detector has been performed by actually applying heat or smoke using a heating tester or a smoke tester depending on the type of the detector. Also, a test in which heat or smoke is directly applied takes human time and contaminates the detector, so apply a test voltage to the circuit inside the fire detector and operate the detector to perform a simulated test. There are various test methods.

[0003] When a fire alarm installed in a dwelling unit is inspected, the resident may not be present. For example, when there is a manager of a dwelling unit, it is possible to enter the dwelling unit by requesting a witness, but this is troublesome. In general, even a fire alarm checker does not like to put another person in the dwelling unit, and the inspection work is often troublesome.

Japanese Patent Application Laid-Open No. Hei 5-34695 discloses that an adapter specified by a frequency has a test voltage applied to the fire detector for the purpose of individually performing an inspection input to the fire detector from outside the dwelling unit from the outdoor display. There is disclosed a fire alarm which generates and generates an operation test. However, in the fire alarm disclosed in this publication, it is necessary to individually adjust the frequency of the signal transmission circuit of the adapter and the outdoor indicator, and the test result is an outdoor buzzer that is sounded based on the operation of the fire receiver. Has been confirmed.

[0005]

In view of this, a fire alarm in which a plurality of fire detectors are connected in parallel between a common line and a line from a receiving unit such as a fire receiver as shown in FIG. Each fire detector has a constant current control means for flowing a predetermined constant current between the common line and the line line based on a signal from the receiving unit, and the receiving unit is connected to the common line after outputting the signal. It is characterized by having counting means for judging the number of fire detectors that responded from the current value between the line and the line line, wherein the receiving unit includes a common line that sums constant currents passing through each responding fire sensor and It has been proposed to determine the number from the current value between the line lines. In this case, a sensor that does not respond cannot be specified, but the presence or absence of an abnormality can be easily and quickly grasped from the number of sensors that responded.

However, when using a microcomputer or the like, in order to read the current value flowing through the common line and the line line, it is necessary to convert the current value into a code signal by analog-to-digital conversion. Also, there is a method in which a current value assuming the number of sensors is prepared on the receiving unit side without reading the current value and compared with a comparator, but the number of parts increases and the circuit configuration becomes complicated. .

[0007]

SUMMARY OF THE INVENTION In view of the above, the present invention provides a fire alarm in which a plurality of fire detectors are connected in parallel between a common line and a line from a receiving unit such as a fire receiver. In the machine, each fire detector has constant current control means for flowing a predetermined constant current between the common line and the line line based on a signal from the receiving unit, and the receiving unit includes a capacitor and a capacitor. It is characterized by having counting means for judging the number of fire detectors responding from the discharge time when discharging between the common line and the line line after the signal output.

Therefore, the number of receiving units can be determined based on the discharge time from the capacitor based on the current value between the common line and the line line obtained by summing the constant currents flowing through the responding fire sensors. In this case, a sensor that does not respond cannot be specified, but the presence or absence of an abnormality can be easily and quickly grasped from the number of sensors that respond.

At this time, in the receiving unit, the discharge time of the capacitor includes the discharge time at a constant current of one fire detector, the discharge time in a constant monitoring state, and the discharge time including the constant current of the responding fire detector. By measuring the time and the time, it becomes possible to determine the number of capacitors that have eliminated the variation of individual capacitors and the constantly monitored current.

Naturally, using the signal output from the receiving section as an inspection signal, each fire detector performs a self-inspection process when receiving the inspection signal, and activates the constant current control means at the time of normal termination, whereby an abnormal condition is detected. The fire detector does not perform constant current control, and the result of the number from the counting means of the receiving unit changes, thereby indicating the presence of an abnormal sensor. In addition, even if the self-inspection is not performed, it is possible to determine whether or not there is a normal number of connections such as a dropout of a fire detector.

[0011]

Embodiments of the present invention will be described below. FIG. 1 is a configuration diagram schematically showing an embodiment of the system.

For example, a plurality of fire detectors 4 provided in each room or the like are connected in parallel to a power / signal line including a common line 2 and a line line 3 drawn from a fire receiver 1 provided in a living room in a dwelling unit. The signal lines 2 and 3 are connected at the rear ends thereof to a terminating resistor 5.

A line switch between the fire detectors 1 on the signal lines 2 and 3 and each fire detector 4 normally connects and connects the common line 2 and the line line 3 to the fire receiver 1. 6
Is arranged.

Normally, each fire detector 4 is connected to the signal lines 2 and 3
The fire monitoring operation is performed by the power supply supplied from the fire receiver 1 through the switch, and when a fire is detected, the switching operation is performed to bring the signal lines 2 and 3 into a low-impedance substantially short-circuit state. The fire receiver 1 detects a substantially short-circuit state based on the switching operation and performs a fire notification operation. At this time, for example, the fire receiver 1 is not provided with a dwelling unit receiver, which is not provided with a dwelling unit receiver (not shown) for performing a fire display on an outdoor display 10 provided and connected to the entrance and connected thereto. , A necessary fire signal is output to the living room receiver.

At the time of inspection, a connector 11 pulled out from the track changer 6 to the outside, for example, to the outdoor display 10 side,
The checker 12 is connected to the connector. On the basis of the inspection operation from the inspection device 12, the line switch 6 outputs an inspection start output to the fire receiver 1 via the inspection output line 9, displays the inspection being performed on the fire receiver 1, and detects each fire. Disconnect the signal lines 2 and 3 to the fire detector 1 from the fire receiver 1
Connect to 2. In this state, the fire receiver 1 performs an inspection display based on the inspection start output of the track changer 6, and the outdoor inspection from the inspector 12 is enabled. At this time, each fire detector 4 operates with the power supply voltage (12 V in this case) supplied from the checker 12 through the signal lines 2 and 3.

FIG. 2 is a schematic circuit diagram of the fire detector 4 used in the system of FIG.

The fire detector 4 includes a constant voltage circuit B2 for supplying a stable voltage and current using the terminals C and L to which the power / signal lines 2 and 3 are connected, respectively, and a circuit for charging the resistor and the capacitor. When a fire is determined by the control circuit B3, a control circuit B3 such as an oscillating circuit (not shown) or a microcomputer that performs interrupt input to the microcomputer based on a constant, a sensor circuit B4 for detecting heat due to a fire based on the temperature characteristics of the thermistor, and the like. And a fire output circuit B1 for switching between the terminals C and L to a low impedance substantially short-circuit state and for turning on a not-shown confirmation lamp. Further, the input side of the signal line 3 is connected to perform an inspection operation. A test signal receiving circuit B6 for detecting an input of a test voltage as a check signal from a terminal L to be tested, and a control circuit B3 for checking operation.
A test circuit B5 for causing the sensor circuit B4 to perform an inspection operation based on the control of the above; a constant current control circuit B7 for flowing a predetermined constant current between the terminals C and L based on the control of the control circuit B3;
Having.

Next, the inspection operation by the control circuit B3 when a thermistor is used is performed in such a manner that a low resistance is connected in parallel to the thermistor in the sensor circuit B4 in order to form a pseudo high temperature state. High temperature conditions can be detected. Then, based on the result, the control circuit B3 determines that the inspection result is normal, turns on the constant current control circuit B7, and flows a predetermined constant current between the terminals C and L.
The timing of the constant current control is simultaneously performed for each fire detector. In the above, the thermistor-type heat detector as a specific example of the fire detector 4 used in the system of FIG. 1 has been described. However, other types such as a photoelectric smoke detector and a flame detector can be used. However, at that time, it is necessary to provide necessary circuits for this system.

The inspection device 12 is entirely controlled using a microcomputer or the like as a counting means (not shown in detail), and a power supply voltage or a test voltage is supplied from the line line 3 to each sensor 4 via the terminal L. Is done. In addition, terminal resistance potentials are artificially given to the signal lines 2 and 3 of the fire receiver 1 via the terminal LP, and the line switch 6 is caused to perform a line switching operation via the terminal ST. Give the inspection start input. In addition, the line switch 6 includes a terminal STt and a terminal STt.
The contact is switched by detecting the inspection start input from the inspector 12 input to the fire receiver 1 via the, and the sensor 4 is constantly connected to each of the detectors 4 connected to the terminal LI to the fire receiver 1. The terminal LO is connected to the terminal Lt to the inspector 12 by contact switching, and at the same time, the terminal LI to the fire receiver 1 is connected to the terminal LP to the inspector 12 by contact switching.
t. In addition, the terminals CI to CO connected to the common line 2 and the terminal Ct from the inspection device 12 are always connected.

As for the operation of the inspection device 12, as shown in FIG. 1, after the inspection device 12 is connected to the connector 11 from outside, the power is turned on. Then, an inspection start input is given from the line switch 6 to the fire receiver 1. And each sensor 4
Signal lines 2 and 3 are switched from the fire receiver 1 to the inspection device 12, and the signal lines 2 and 3 of the fire receiver 1 are given pseudo-impedance by the terminating resistance by the inspection device 12 to receive the fire. The disconnection display of the machine 1 is not performed.

In this state, an inspection operation is started. When the inspection operation is started, a voltage limiting circuit (not shown) for supplying a power supply voltage from the inspector 12 is operated to operate the terminal L.
The test voltage supply as a check input is started. FIG. 4 schematically shows the current value between the signal lines 2 and 3 during the above operation. In FIG. 4, the left side of the dotted line is a receiving unit such as the inspection device 12, and the terminating resistor 5 and a part of the n connected fire detectors 4 are simply shown.

First, in the normal state, the terminals C and L
When a constant voltage is supplied in between, a predetermined current Ir passing through the terminating resistor 5 flows. At this time, since a small monitoring current is flowing through each of the fire detectors 4, in a normal state, the current is exactly a predetermined current Ir + α. However, since this α component can be handled in the same manner as Ir, it is included in Ir. You can think.

In this state, the fire detectors 4 connected between the signal lines 2 and 3 are supplied with the test voltage by the test signal receiving circuit B6, and the inspection input is performed to the control circuit B3.
Then, the fire detector 4 outputs a pulse signal for starting the inspection operation from the inspector 12, and each fire detector 4 receives the pulse signal and operates the test circuit B5 based on the control of the control circuit B3 to activate the sensor circuit B4. Inspection to. When the sensor circuit B4 is normal, the control circuit B3 of each fire detector 4 operates the constant current control circuit B7 to discharge a predetermined constant current between the signal lines 2 and 3. At this time, one fire detector 4
Is a predetermined constant current flowing through the operation of the constant current control circuit B7, the current Id is more normal than the normal state n
It will increase by the number.

Assuming that the normal current is I1 and the current of the inspection result is I2, I1 = Ir, I2 = n ＝ Id + Ir
However, the inspection device 12 determines the number of normal detectors as a result of the inspection based on the change in the current value, as compared with before the inspection is performed by the method described later. By operating in this way, it is possible to determine whether the number is normal as a whole by grasping the normal number without taking in the inspection results individually.

Next, a method of calculating the number of sensors will be described with reference to FIG. In FIG. 3, similarly to FIG.
And a part of n fire detectors 4 connected in a simplified manner.

In the normal state, each fire detector 4 is supplied with a constant voltage from the receiving unit side, and at this time, the contact a is closed. Before starting the operation of calculating the number of sensors, first, the discharge time t3 of the capacitor Co for a predetermined constant current is measured. For this reason, first, the capacitor Co is supplied from the constant voltage supply source.
Contact b is closed. After waiting until the potential of the capacitor Co becomes sufficient, the contact d is closed and the contact b is opened. In this state, the comparator CM determines that the potential of the capacitor Co is discharged through the contact d and the constant current limiting circuit 4 'for controlling the current to the predetermined constant current Ir, and has dropped to the predetermined potential by resistance division. Measure the time until you do it. Then, the contact d is opened.
The microcomputer (not shown) as a counting means calculates the time from the opening of the contact b to the operation of the comparator CM as the discharge time t.
3 is stored in a storage unit (not shown).

Next, the discharge time t1 in the normal state is measured. Similarly, the capacitor C is first supplied from the constant voltage source.
To charge o, contact b is closed. After waiting until the potential of the capacitor Co becomes sufficient, the contacts c to the signal lines 2 and 3 are closed, and the contact a from the power supply voltage (in this case, the test voltage) is opened, and the contact b is opened. I do. In this state, the potential of the capacitor Co is changed to the contact c,
In the normal state, the monitoring current is discharged through the signal lines 2 and 3, and the time until the comparator CM determines that the voltage has dropped to a predetermined potential is measured. Then, the contact a is closed and the contact c is opened. The microcomputer serving as a counting means (not shown) stores the time from the opening of the contact b to the operation of the comparator CM in the storage means (not shown) as the discharging time t1.

Then, the discharge time t2 in a state where the responding fire detector 4 is controlled at a constant current is measured. First,
In order to make each fire detector 4 respond, a check signal such as a pulse signal is transmitted, and similarly, the contact b is closed to charge the capacitor Co from the constant voltage supply source. Capacitor C
After making the potential of o sufficient so that each fire sensor can respond to the inspection result, the contact c to the signal lines 2 and 3 is closed, the contact a from the power supply voltage is opened, and the contact b is opened. . In this state, the potential of the capacitor Co is changed to the contact c.
And a predetermined current value as a result of the constant current control of the responding fire detector 4 is discharged through the signal lines 2 and 3 through which a current matching the monitoring current in the normal state flows, and similarly drops to a predetermined potential. The time until the comparator CM determines that the operation has been performed is measured. Then, the contact a is closed and the contact c is opened. The microcomputer as counting means (not shown) stores the time from the opening of the contact b to the operation of the comparator CM in the storage means (not shown) as the discharge time t2.

When a constant voltage is supplied between the terminals C and L from the receiving unit side in a normal state, a predetermined current I passing through the terminating resistor 5 is supplied.
r flows. At this time, since a small monitoring current is flowing through each of the fire detectors 4, in a normal state, the current is exactly a predetermined current Ir + α. Think. Assuming that a predetermined constant current flowing from one fire detector 4 by the operation of the constant current control circuit B7 is Id, the current Id is increased by a normal number n from the normal state. That is, the constant current is I1, the inspection result current is I2, and the predetermined constant current is I3.
Then, I1 = Ir, I2 = n · Id + Ir, I3 =
Id. Here, since the capacity of the capacitor Co and the constant voltage supply are constant, I1 · t1 = I2 · t2 = I3
T3, and since I2 = I1 + nI3, the number n
Can be calculated by n = t3 (t1−t2) / (t1 · t2).

As described above, it is sufficient to take in the discharge time from the capacitor Co only by one port of the microcomputer (not shown), and it is not necessary to perform the analog-to-digital conversion. This is a simple and inexpensive method.

In addition to the above-described method, a method of comparing the time by providing a plurality of detectors and a pseudo signal portion of the terminating resistor on the receiving unit side can be used. However, the number of circuit elements increases and the circuit configuration becomes complicated.

In the above embodiment, the inspection operation is performed by the inspection device 12 as the receiving unit. However, the inspection may be performed by the fire receiver 1, and the inspection input includes the voltage displacement from the power supply voltage to the test voltage and the pulse signal. Alternatively, a code signal, a change in frequency, or the like may be used, and the response of the fire detector 4 may be simply a constant current control as a signal response without performing a self-check.

Further, as a circuit configuration in the fire detector 4, a fire output circuit B1 and a constant current control circuit B7 are separately provided. However, the fire output circuit B1 may perform constant current control. In this case, the switching operation, which is a fire signal, needs to be performed by constant current control as the entire system.

As described above, in the above embodiment, a fire alarm in which a plurality of fire detectors 4 are connected in parallel between a common line 2 and a line line 3 from a receiving unit such as a fire receiver. Each of the fire detectors 4 includes a constant current control unit (circuit) B7 for flowing a predetermined constant current Id between the common line 2 and the line line 3 based on a signal from the receiving unit. The number n of fire detectors responding from the capacitor Co and the discharge time when discharging between the common line 2 and the line line 3 after outputting the signal from the capacitor Co
Receiving means, the receiving unit is provided with a common line 2 which is the sum of the constant currents Id flowing through the responding fire sensors.
The number n can be determined based on the discharge time from the capacitor Co based on the current value between the line lines 3. In this case, a sensor that does not respond cannot be specified, but the presence or absence of an abnormality can be easily and quickly grasped from the number of sensors that respond.

At this time, in the receiving unit, the discharge time of the capacitor including the discharge time at the constant current of one fire detector, the discharge time in the constantly monitored state, and the discharge time including the constant current of the responding fire detector. By measuring the time and the time, it becomes possible to determine the number of capacitors that have eliminated the variation of individual capacitors and the constantly monitored current.

Naturally, using the signal output from the receiving unit as an inspection signal, each of the fire detectors 4
By performing the self-inspection process and activating the constant current control means (circuit) B7 at the time of normal termination, the abnormal fire detector does not perform the constant current control, and the result of the number from the counting means of the receiving unit changes. You can see the presence of the abnormal sensor. In addition, even without self-inspection, fire detector
It can be grasped whether there is a normal number of connections.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing a system.

FIG. 2 is a schematic block circuit diagram of the fire detector of FIG. 1;

FIG. 3 is a schematic diagram simply showing a discrimination method from the system of FIG. 1;

FIG. 4 is a schematic diagram simply showing a state of a current in the system of FIG. 1;

[Explanation of symbols]

 2, 3 signal line 4 fire detector 12 checker

Claims (2)

[Claims] 1. A fire alarm in which a plurality of fire detectors are connected in parallel between a common line and a line line from a receiver such as a fire receiver, wherein each of the fire detectors And a constant current control means for causing a predetermined constant current to flow between the common line and the line line based on the signal of the common line and the line line after the signal is output from the capacitor. A fire alarm comprising counting means for judging the number of fire detectors responding from the discharge time when discharging between the fire detectors. 2. The signal output from the receiving unit is an inspection signal, and each fire detector receives the inspection signal when receiving the inspection signal.
2. The fire alarm according to claim 1, wherein a self-inspection process is performed and the constant current control means is activated at the time of normal termination.